Finding drive ratio?

Wide Open

Seaman
Joined
May 29, 2007
Messages
57
Is it possible to determine the drive ratio from the SN? I am looking for a new prop and the Mercury prop selector wants to know the gear ratio. I of course don't have any idea but based on the previous owner I assume it is whatever it came with stock. The boat is up in the sky because I am working on the trailer brakes so I don't want to climb up in there and turn the engine unless I have no other choice. The drive is a 1990 Alpha I SN 0D309970.
 

wire2

Lieutenant Commander
Joined
Jun 25, 2007
Messages
1,584
Re: Finding drive ratio?

What engine? Typically, I believe V8's are 1.5:1 (or 1.47:1), 4's & 6's are 2:1, (1.98)
 

Wide Open

Seaman
Joined
May 29, 2007
Messages
57
Re: Finding drive ratio?

Sorry didn't realize the engine mattered.
It is a 1990 4.3 (carb). The options according to the Mercury are: 1.47, 1.62, 1.81, and 2.0.
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: Finding drive ratio?

Engine and elevation, determine which ratio would have been installed.
 

njlarry

Petty Officer 1st Class
Joined
Sep 13, 2005
Messages
330
Re: Finding drive ratio?

Have you learned your ratio yet? Have you emailed Merc or is the info on their web?
 

Wide Open

Seaman
Joined
May 29, 2007
Messages
57
Re: Finding drive ratio?

Have you learned your ratio yet? Have you emailed Merc or is the info on their web?

No not yet. I have been working on the brakes and am still having issues so I will get back to the drive ratio once the brakes work. I haven't emailed Merc yet nor have I been able to find anything on their website.
 
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